Well bit



March 17, 1936.

J. c. WRIGHT WELL BIT 'Filed April 2, 1954 f lifl..

Patented Mar. 17, 1936 PATENT- OFFICE 2,034,073 y WELL BIT Jesse C. Wright, Los Angeles, Globe Oil Tools Company, corporation of California Application April 2, 1934, Serial No. 718,569 (Cl. Z55-72) 9 Claims.

This invention relates to a well tool and has particular reference to a well drilling bit for use in the rotary method of well drilling. A general object of the invention is to provide a simple, practical well bit that is rapid and effective in operation.

Another object of the invention is to provide a well bit including cutting means for making an annular cut in the earth formation to leave a core, a cutting means to destroy or cut away the core thus formed and means for handling the circulation fluid so that it thoroughly flushes the cutting means and is effective in eroding and softening the core to materially aid the second mentioned cutting means in destroying the core.

Another object of the invention is to provide a well bit comprising a sleeve or body part having scraper type cutting means on its lower end which make an annular cut leaving a core which is received inthe tubular body part, and roller cutters in the upper end of the tubular body part for acting on the upper end of the core to destroy or cut away the core.

Another object of the invention is to provide a well bit comprising a tubular body part having cutting blades or teeth on its lower end for making an annular cut and to leave a core which is received in the tubular body part, cutters for engaging the upper end of the core to cut it away and means discharging circulation fluid downwardly onto the core to wash some of the core away and to soften the remainder of the core, the tubular body part operating to confine the core so that the fluid is made to flow downwardly around it and discharge from the lower end of the body to effectively flush the blades or teeth on the end of the tubular body part.

A further object of the invention is to provide an improved bit construction involving a simple and dependable means for mounting roller cutters.

Other objects and features of the invention may become apparent from the following detailed description of a typical preferred form and application of the invention throughout which description reference may be had to the accompanying drawing, in which:

Fig. 1 is a longitudinal detailed sectional view of the bit provided by the invention illustrating it in operation in a well. Fig. 2 is a transverse detailed sectional View taken substantially as indicated byline 2-2 on Fig. 1. Fig. 3 is a longitudinal detailed sectional view of the body or shank, being 'a View taken in a. plane at right angles to Calif., assignor to Los Nietos, Calif., a,

the plane of sectioning of Fig. 1 and Fig. 4 is a bottom view of the shank or body.

Thewell drilling bit of the present invention includesgenerally a shank or body I0, lower or outer cutting means II on the lower end of the body I0 for making an annular cut A in the formation which leaves a core C, and inner cutting means I2 for destroying or Vremoving the core C.

The body I0 includes a shank portion I3 provided at its upper end with suitable means for connecting with the lower end of a drilling string. In the particular form of the invention illustrated in the drawing a tapered screw threaded pin I 4 is provided on the upper end of the shank portion I3 to facilitate connection with a drill collar, or the like, on the lower end of a drilling string of drill pipe. An outwardly projecting annular ange is provided on the body at the lower end of its shank portion I3. The lower or underside of the flange forms a downwardly facing annular shoulder I5. A thread I6 is provided on the exterior of the body I0 and extends downwardly from the shoulder I5. The body III includes a lower portion I'I of cylindrical cross section which extends downwardly from the lower end of the thread I 6. A socket or recess I8 extends upwardly into the lower end of the body portion I 'I to receive or carry the inner cutting means I2, as will be subsequently described. The recess I8 preferably extends transversely through the body portion I'I from one side to the other. The inner and outer walls I9 of the recess I8 are inclined downwardly and outwardly relative to the central longitudinal axis of the body and are preferably substantially parallel. The recess I8 is eccentric or offset from the central longitudinal axis ofthe body having the lower end of its outer Wall I9 adjacent the periphery of the portion I'I and having the lower end of its inner wall I9 adjacent the central vertical axis of the body. In the preferred construction the recess I8 is sufficiently large or wide to intersect the longitudinal axis of the body. The lower end of the body or body portion I'I may be frusto-conical,

tapering downwardly and inwardly toward its center.

The outer cutting means I I includes a sleeve or tubular part 20 attached to the-body l0 to form a downwardly extending continuation thereof and cutting blades or teeth 2 I- on the lower end of the tubular part 20. The tubular part 20 is a carrier or mounting for the cutting teeth 2| and surrounds or encloses the core C to insure an effective downward circulation of fiuid around the core. In accordance with the invention the tubular part 20 telescopes over the lower portion l1 of the body having a cylindrically curved internal wall 22 contacting with the periphery of the portion |1. The upper portion of the part 20 is screw threaded onto the body I0 having an internal thread cooperating with the body thread I6. The upper end of the tubular part 20 bears upwardly against the shoulder I5. The opening 23 in the portion of the tubular part 2| which projects downwardly from the body may be of increased diameter.

The cutting parts 2| of the means are in the nature oi scraping blades or teeth which operate to make the annular cut A in the earth formation when the drill is rotated and fed downwardly in accordance with the usual practice in rotary drilling. 'In the particular bit structure illustrated in the drawing, the teeth 2| are formed on the tubular part 20, it being apparent that they may be provided on a detachable ring or shoe, on the lower end of the part 20. There is a plurality of circumferentially spaced cutting teeth 2| projecting downwardly from the lower end of the tubular part 2li. The teeth 2| project inwardly and outwardly from the tubular part 20 to cut an annular channel of suincient width to pass or receive the tubular part 20 with the desired clearance. The particular cutting teeth 2| illustrated in the drawing are disposed substantially radially relative to the central vertical axis of the tool and are provided with normal or substantially horizontal lower cutting edges. During the drilling operation when the drill is rotated on the lower end of a drilling string the annular series of cutting teeth 2| penetrates or cuts downwardly in the earth formation, making the cut A and providing the upstanding central core C which extends upwardly into the tubular part 20.

The inner cutting means I2 acts on or engages the upper end'oi the core C to remove or cut away the core as it is formed by the outer cutting means 'I'he cutting means |2 includes one or more roller cutters 30 rotatably supported on a bearing or pin 3|. The pin 3| extends across the recess |8 to rotatably support the cutters 30 in positions where they project downwardly into the upper end of the opening 23 to engage the core. The invention provides novel means for removably holding the pin 3| in its proper cutter supporting position. A lateral opening 32 ext-ends inwardly -from the periphery of the lower body portion 1 to communicate with the recess I8 at its outer wall I9. A cylindrical socket 33 is provided in the inner wall I3 of the recess I8 in axial alignment with the opening 32. The axes of the opening 32 and socket 33 are inclined upwardly and outwardly with respect to the central longitudinalV axis of the body I0 and lie in a plane substantially radial of the central longitudinal axis of the body. The cutter carrying pin 3| has its inner end portion supported in the socket 33 and its outer end portion carried in the opening 32. The pin 3| supported as just described is inclined upwardly and outwardly. The outer end of the pin 3| is conical to be engaged by the interior of the tubular part 20 which eectively holds the pin against longitudinal movement. Means is provided for holding the pin 3| against rotation. A transverse opening 35 is provided in the body I 0 to intersect the socket 33 at its inner wall. A diametrical groove 36 of substantially semi-circular transverse cross section is provided in the inner end of the pin 3| to register with the glOQV@ Portion bodiment of the invention illustrated in the drawing includes two like roller cutters 30. I have shown the roller cutters 30 directly rotatably supported on the pin 3|, it being apparent that the cutters 30 may be rotatably mounted on the pin through suitable bearings if desired or found practical. A spacing washer 40 is provided on the pin 3| between the two cutters 30 and thrust washers 4| are provided between the walls I9 of the recess and the outer ends of the cutters. The cutters 30 are cylindrical in their general conguration and are provided with peripheral cutting parts or teeth 42. The cutters 30 mounted as just described are independently rotatable on axes inclined upwardly and outwardly with respect to the central longitudinal axis of the tool. The cutters 30, therefore, rotate in planes inclined downwardly and outwardly. The cutters 30 are positioned so that their paths of activity or engagement with the upper end of the core cover substantially the entire end of the core. The path oi' movement of the innermost cutter 30 extends outwardly from a point immediately adjacent the central longitudinal axis of the bit. The roller cutters 30 in rotating in planes inclined downwardly and outwardly provide the core C with a dished or concave upper end.

The invention includes means for handling or discharging the circulation iluid in a manner to thoroughly iiush the roller cutters 30, erode and soften the core C, and ush the cutting teeth 2 A central longitudinal duct 45 extends downwardly into the body I0 from its upper end. A branch port 46 communicates with the lower end of the duct 45 and discharges fluid downwardly into the upper end of the recess I8. A bean 41 is provided in the lower end of the port 46 and has a reduced fluid opening which provides for an increase in the velocity of the discharging fluid. It will be apparent that the iluid under pressure discharging from the bean 41 thoroughly ilushes the roller cutters 30. After flushing the cutters 30 the uid flows downwardly through the opening 23 around the core C to erode and soften the core and then pass upwardly around the lower end of the tubular part 20 to clean and ilush the teeth 2|. A branch passage 5|! extends downwardly and outwardly from the lower end pmt of the duct 45 to discharge into the opening 23 at a, point adjacent the peripheral edge of the lower end of the body. A bean 5| having a reduced fluid opening is provided in the lower end of the passage 50 to discharge the uid at an increased velocity. The circulation uid under pressure discharged from the bean 5| strikes the upper corner portion of the coreC to erode or wash away that part of the core. Afterstrlking the upper portion of the oo'e the uid flows downwardly around the core to discharge from the lower end of the tubular part 20 in amanner to provide eiective circulation and turbulence in the bottom of the bore and to ilush the teeth 2 I. As the tubular part 20 completely surrounds and connnes the major'portion of the core C the circulation fluid discharged from the beans 41 and 5| is made to flow or pass downwardly through the comparatively narrow annular passage between the core C and the interior of the tubular part 20. This fluid passing downwardly through the tubular part 20 has an effective erosive action on the earth formation of the core and softens the portion of the core that is not eroded or washed away.

In assembling the bit the roller cutters 30 and the washers 40 and 4| are held in their proper respective positions in the recess I8 while the pin 3| is passed inwardly through the opening 32 and cutters to seat in the socket 33. 'I'he pin 3| is then positioned so that its groove 36 is in alignment with the opening 35 and the key 31 is passed into the opening 35 to key the pin 3| against turning. With the cutter carrying pin 3| and the key 31 in position the tubular part 20 may be threaded onto the body I to dependably lock the pin and key against movement. The exterior of the tubular part 20 may be provided with spaced sockets or notches 60 to facilitate engagement of the tubular part by a turning or holding tool.

It is believed that the operation of the well drilling bit provided by the present invention will be readily understood from the foregoing detailed description. The bit may be attached to the lower end of a drilling string which is rotated in the usual manner to operate the bit. 'I'he plurality of spaced teeth 2| cut the comparatively narrow annular channel A in the earth formation and leave the core C which is received in the tubular part 20. The roller cutters 3| have cutting engagement with the upper end of the core to remove or destroy the core. Circulation uid is continuously pumping downwardly through the drilling string to discharge from the beans 41 and 5|. The roller cutters 30 are fully flushed by the Huid discharged from the bean 41. Fluid discharged from the bean 5| washes away the upper corner part of the core C materially reducing the size of the core. The fluid discharged from the beans ,41 and 5I is conilned by the tubular part 20 to pass downwardly through the comparatively narrow annular space surrounding the core C and is accordingly made to erode the core. In addition to eroding or washing away the core the circulation fluid softens the core so that it is easily cut away by the roller cutters 30. It is well recognized in the art of well drilling that an unconfned or free portion of earth formation such as the core C is more readily and quickly cut away than a continuous uncut part of the formation. Further, it is recognized that cutters or cutting means making a narrow annular cut in the earth formation are very rapid and eicient in operation. The bit of the present invention provides the lower or outer cutting means which makes a comparatively narrow annular cut in the earth formation and the inner cutting means I2 acts on the upstanding core C and is, therefore, particularly efllcient. Further, the series of circumferentially spaced cutting teeth 2| on the lower end of the tubular part 2U out through the earth formation without being deflected so that the bit operates to make a straight vertical bore.

Having described only a typical form or embodinent of the invention, I do not Wish to limit myself to the specific details set forth, but wish to reserve to myself any changes or variations that may appear to those skilledin the art or that fall within the scope of the following claims:

Having described my invention, I-claim:

1. A well bit including a shank body having means at its upper end for connecting with a drilling string, body to surround its lower portion and projecting downwardly from the lower end of the body, cutting means on the lower end of the tubular part for making an annular cut which leaves a core to be received in the tubular part, there being an opening in said portion of the body whose outer end is closed by the tubular part, a pin carried in said opening where it is held against displacement by the tubular part, and a cutter rotatable on the pin to engage the upper end of the core and cut away the core.

2. A well bit including a shank body having a recess in its lower end and an opening communicating with the recess, means at the upper end of the body for connecting with a drilling string, a pin supported in the opening and extending across the recess, a tubular part threaded to the body to surround the lower portion of the body and close the end of said opening and thus prevent displacement of the pin, the tubular from the lower end of the body, cutting means on the lower end of the tubular part to make an annular cut and leave a core for reception in the tubular part, and a cutter on the pin for cutting away the core.

3. A well bit including a shank body having a recess in its lower end and an opening communicating with the recess, means at the upper end of the body for connecting with a drilling string, a pin supported in the opening and extending across the recess, a tubular part threaded to the body to surround the lower portion of the body and close the end of said opening and thus prevent displacement of the pin, the tubular part projecting downwardly from the lower end of the body, cutting means on the lower end of the tubular part to make an annular cut and leave a core for reception in the tubular part, and a roller cutter .carried by the pin to rotate about an inclined axis and project into the tubular part to engage the upper end of the core to cut away the core.

4. A well bit including a shank, a tubular imperforate part threaded on the shank to project downwardly beyond the lower end of the shank, cutting means on the lower end of the tubular part for making an annular cut which leaves a core to be received in the tubular part, and cutting means projecting from the lower end of the shank to extend into the tubular part and cut away the core, there being a passage in the shank discharging iluid into the tubular part from a point spaced from the last mentioned cutting means to erode the core and then ow downwardly through the tubular part around the core.

5. A well bit including a body having a recess in its lower end and an opening communicating with the recess, a pin supported in the opening and extending across the recess, there being a second opening in the body, a key in the second opening engaging the pin to hold it against ro-` tation, a tubular member surrounding the lower a tubular part threaded to the portion to close the outer ends of both of said openings and projecting from the lower end of the body, cutting means on the lower end of the tubular part making an annular cut to leave a core to be receivedin the projecting portion of the tubular part, and a cutter carried by the pin to engage the upper end of the core.

6. A well bit including a shank body having means at its upper end for connecting with an operating string, an inner cutting means comprising a pin removably carried in an opening in the body, and a cutter on the pin, outer cutting means comprising a series of cutting teeth related to make an annular cut and leave a core to be cut away by said cutter, and a carrier for said teeth supported on the body where it closes the end of the opening and holds the pin against displacement.

'7. A well bit including a body, an inner cutting means comprising a pin removably carried by the body, and a cutter on the: pin, outer cutting means comprising a series'oi cutting teeth related to make an annular cut and leave a core to be cut away by said cutter, and a tubular carrier threaded on the body to hold the pin against displacement and to project from the lower end of the body to support the teeth below the body and surround the core.

8. A well bit including, a body having a recess in its lower end and an opening extending inwardly from its periphery to join the recess at its outer wall, the inner wall of the recess having a socket, a pin extending across the recess and having its end portions supported in the opening and socket, roller cutters rotatable on the pin, means holding the pin against rotation, a tubular part threaded on the body to cover the outer end of said opening and projecting downwardly from the lower end of the body, and cutting teeth on the lower end of the tubular part 5 for making an annular cut to leave a'. core to extend into the tubular part and be engaged by the roller cutters. Y

9. A well bit including, a body havinga recess in its lower end and an opening extending in- 10 wardly from its periphery to join the recess at its outer wall, the inner wall of the recess having a socket, a pin extending across the recess and having its end portions supported in the opening and socket, roller cutters rotatable on 15 the pin, means holding the pin against rotation, the cutters being cylindrical in their general configuration and rotatable about axes inclined out'- wardly and upwardly with respect to the vertical axis of the bit, a tubular part threaded on the body to cover the outer end of said opening and projecting downwardly from the lower end of the body, and cutting teeth on the lower end of the tubular part for making an annular cut to leave a core to extend into the tubular part 25 and be engaged by the roller cutters.

JESSE C. WRIGHT. 

